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Process of Asexual & Sexual Reproduction (#5) 

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Process of Asexual & Sexual Reproduction (#5) 

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Process of Asexual & Sexual Reproduction (#4) 

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Process of Asexual & Sexual Reproduction (#4) 

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Process of Asexual & Sexual Reproduction (#3) 

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Process of Asexual & Sexual Reproduction (#3) 

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Process of Asexual & Sexual Reproduction (#2) 

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Process of Asexual & Sexual Reproduction (#2) 

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Mr. Lima explains the differences and similarities between sexual and asexual reproduction and discuses advantages/-disadvantages of each. To watch the rest of this lecture series, visit: http://www.youtube.com/playlist?list=PL99CF3DD272906BBB&feature=view_all

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Process of Asexual & Sexual Reproduction (#1)

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Process of Asexual & Sexual Reproduction (#1)

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Asexual reproduction is the reproduction that occurs without using any interaction between the 2 different members of a species. Cells typically divide using mitosis, in which each of the chromosomes are copied before the nucleus begins to divide, with each of the new cells receiving identical genetic information for that organism. Sexual reproduction is the reproduction that requires with a male and a female of the same species to share their genetic material. Special cells that are called gametes are produced in meiosis, which halves the number of chromosomes in each resulting cell. These cells are haploid gametes. Fertilization occurs when 2 gametes. There is one from a male and one from a female. They combine, producing what's called a diploid zygote with its own individual genetic information.

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Plant Classification for Ecological Purposes: is there a Role for Genome Si...: Discover GALILEO

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By Chy Allen and Ray Allen, Founders of AmericanMeadows.com

Here's a quick explanation of how plants are classified from Kingdom, the highest division, all the way to Variety, the lowest. Remember, a common wildflower like Black-eyed Susan is called Rudbeckia hirta. Rudbeckia is the Genus name. Hirta is the Species. You'll find these two sub-divisions way down on this list.

An Example of Plant Classification

Black-eyed Susan
Rudbeckia hirta

Source: USDA

Explanations of Classifications (beginning with "Class")

I. Class

Class divides plants into the two large groups, Dicots and Monocots.

A. Dicotyledons (Dicots are plants with two seed leaves. This huge group, with approximately 2/3 of all flowering plants, includes most all wildflowers. Dicots have "net-veined" leaves, which means they have the familiar leaves with center vein plus branching veins running from it.

B. Monocotyledons (Monocots, plants with one seed leaf, are the grasses and other simpler plants, and make up about 1/3 of all flowering plants. Monocots have parallel-veined leaves.)

II. Subclass (Not used with all species.)

A group of related plant families classified in the order in which they are believed to have developed their differences from a common ancestor. There are six "superorders" with each one's name ending in "idae."

III. Order (Not used with all species.)

The classes are further sub-divided into "orders" whose names end in "ales."

IV. Family

Each order is divided into families. Each member of a plant family shares many botanical features. This is the highest classification group normally referred to. Modern classification assigns a type of plant to each family as an example of that family's characteristics as distinguishable from other families. The names of families end in "aceae." Click here for a list of Wildflower Families

V. Sub-Family (Not used with all species.)

A sub-division of a family in which plants are grouped according to botanical differences within the same family. Sub-families end in "oideae."

VI. Tribe (Not used with all species.)

A further family division based on less significant botanical differences. Tribes end in "eae."

VII. Sub-Tribe (Not used with all species.)

A further division based on even smaller botanical differences, usually only recognizable by professional botanists.

VIII. Genus

This is the part of plant nomenclature that is the most familiar. For example, Papaver is the genus for Poppy. Plants in a genus are easily recognizable as belonging to the same group. The name of the genus should always be capitalized. Example: Red Poppy is Papaver rhoeas.

IX. Species

This is the level of classification that defines the individual plant. Here some aspects of the plant are more specifically defined - color, leaf shape, or place where or by whom it was discovered. The use of the genus and species names together always refer to only one plant. The species name is written after the genus and is never capitalized. Example: Rudbeckia hirta

X. Variety (Not used with all species.)

To receive this added piece of nomenclature, a plant must be only slightly different from a certain species, but not different enough to be granted its own species name. When used, the Variety name follows the Genus and Species names with the abbreviation, "var," followed by the full variety name in small letters. The wildflower Scarlet Flax is a good example: Linum grandiflorum var rubrum. In Latin, this tells you that this is a Flax (linum) with large flowers (grandiflorum) that happen be red (rubrum). (Most of the family is not red-flowered.) Most wildflowers do not have this extra little added-on name, (for example, Rudbeckia hirta does not.) but it's important when needed.

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Here's a quick explanation of how plants are classified from "Kingdom", the highest division, all the way to "Variety", the lowest. Remember, a common wildflower like Black-eyed Susan is called Rudbeckia hirta. Rudbeckia is the "Genus" name. Hirta is the "Species." You'll find these two sub-divisions way down on this list.

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Plants are classified by the type of photosynthetic pathway that they possess. Scientist have then sort them due to their similarities and differences. The system of classification that they use is called taxonomy.  It typically features both English and Latin terms. You would have to know the common and scientific name as they are both typically different. The order Plants are classified in are Kingdom, Phylum, Class, Order, Family, Genus, and Species. This can be such as vascular and nonvascular plants. The main types are Bryophytes, Tracheophytes, Gymnosperms, and Angiosperms

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Galileo Article

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Cloning: Revolution or Evolution in Animal Production?: Discover GALILEO

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Website

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The term cloning describes a number of different processes that can be used to produce genetically identical copies of a biological entity. The copied material, which has the same genetic makeup as the original, is referred to as a clone. Researchers have cloned a wide range of biological materials, including genes, cells, tissues and even entire organisms, such as a sheep.

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The term cloning describes a number of different processes that can be used to produce genetically identical copies of a biological entity. The copied material, which has the same genetic makeup as the original, is referred to as a clone.

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There are roughly 9 main steps of cloning. The 1st step is the chemically cutting of the gene needed to study from the DNA strand. The 2nd step, it is to attack a target gene to a tiny circular part of DNA. Both of these together are called plasmid in which they are the transporting part for the gene. The 3rd step is to put the plasmid into an E. coli cell aka bacteria. As each of these bacterial cells divide, each of them has a copy of plasmid with the gene. The 4th step is to grow more of these cells. When the appropriate number is achieved, split the bacteria cell with a chemical that penetrates the cell wall. The 6th step is to collect only the plasmids with the gene. The 7th step is to put these plasmids into human being cells. The 8th step is to wait and eventually the plasmid will be in the host cell DNA and the newer gene should change the proteins. The final step is to observe physical changes between the plasmid cells and the ones not containing them.

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PDF photosynthesis article

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website explaining photosynthesis

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Why is photosynthesis important?

What is the basic formula for photosynthesis?

Which organisms can photosynthesize?

Read a brief summary of this topic

photosynthesis, the process by which green plants and certain other organisms transform light energy into chemical energy. During photosynthesis in green plants, light energy is captured and used to convert water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds.

It would be impossible to overestimate the importance of photosynthesis in the maintenance of life on Earth. If photosynthesis ceased, there would soon be little food or other organic matter on Earth. Most organisms would disappear, and in time Earth's atmosphere would become nearly devoid of gaseous oxygen. The only organisms able to exist under such conditions would be the chemosynthetic bacteria, which can utilize the chemical energy of certain inorganic compounds and thus are not dependent on the conversion of light energy.

Energy produced by photosynthesis carried out by plants millions of years ago is responsible for the fossil fuels (i.e., coal, oil, and gas) that power industrial society. In past ages, green plants and small organisms that fed on plants increased faster than they were consumed, and their remains were deposited in Earth's crust by sedimentation and other geological processes. There, protected from oxidation, these organic remains were slowly converted to fossil fuels. These fuels not only provide much of the energy used in factories, homes, and transportation but also serve as the raw material for plastics and other synthetic products. Unfortunately, modern civilization is using up in a few centuries the excess of photosynthetic production accumulated over millions of years. Consequently, the carbon dioxide that has been removed from the air to make carbohydrates in photosynthesis over millions of years is being returned at an incredibly rapid rate. The carbon dioxide concentration in Earth's atmosphere is rising the fastest it ever has in Earth's history, and this phenomenon is expected to have major implications on Earth's climate.

Requirements for food, materials, and energy in a world where human population is rapidly growing have created a need to increase both the amount of photosynthesis and the efficiency of converting photosynthetic output into products useful to people. One response to those needs-the so-called Green Revolution, begun in the mid-20th century-achieved enormous improvements in agricultural yield through the use of chemical fertilizers, pest and plant- disease control, plant breeding, and mechanized tilling, harvesting, and crop processing. This effort limited severe famines to a few areas of the world despite rapid population growth, but it did not eliminate widespread malnutrition. Moreover, beginning in the early 1990s, the rate at which yields of major crops increased began to decline. This was especially true for rice in Asia. Rising costs associated with sustaining high rates of agricultural production, which required ever-increasing inputs of fertilizers and pesticides and constant development of new plant varieties, also became problematic for farmers in many countries.

A second agricultural revolution, based on plant genetic engineering, was forecast to lead to increases in plant productivity and thereby partially alleviate malnutrition. Since the 1970s, molecular biologists have possessed the means to alter a plant's genetic material (deoxyribonucleic acid, or DNA) with the aim of achieving improvements in disease and drought resistance, product yield and quality, frost hardiness, and other desirable properties. However, such traits are inherently complex, and the process of making changes to crop plants through genetic engineering has turned out to be more complicated than anticipated. In the future such genetic engineering may result in improvements in the process of photosynthesis, but by the first decades of the 21st century, it had yet to demonstrate that it could dramatically increase crop yields.

Another intriguing area in the study of photosynthesis has been the discovery that certain animals are able to convert light energy into chemical energy. The emerald green sea slug (Elysia chlorotica), for example, acquires genes and chloroplasts from Vaucheria litorea, an alga it consumes, giving it a limited ability to produce chlorophyll. When enough chloroplasts are assimilated, the slug may forgo the ingestion of food. The pea aphid ( Acyrthosiphon pisum) can harness light to manufacture the energy-rich compound adenosine triphosphate (ATP); this ability has been linked to the aphid's manufacture of carotenoid pigments.

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General characteristics

Development of the idea

The study of photosynthesis began in 1771 with observations made by the English clergyman and scientist Joseph Priestley. Priestley had burned a candle in a closed container until the air within the container could no longer support combustion. He then placed a sprig of mint plant in the container and discovered that after several days the mint had produced some substance (later recognized as oxygen) that enabled the confined air to again support combustion. In 1779 the Dutch physician Jan Ingenhousz expanded upon Priestley's work, showing that the plant had to be exposed to light if the combustible substance (i.e., oxygen) was to be restored. He also demonstrated that this process required the presence of the green tissues of the plant.

In 1782 it was demonstrated that the combustion-supporting gas (oxygen) was formed at the expense of another gas, or "fixed air," which had been identified the year before as carbon dioxide. Gas-exchange experiments in 1804 showed that the gain in weight of a plant grown in a carefully weighed pot resulted from the uptake of carbon, which came entirely from absorbed carbon dioxide, and water taken up by plant roots; the balance is oxygen, released back to the atmosphere. Almost half a century passed before the concept of chemical energy had developed sufficiently to permit the discovery (in 1845) that light energy from the sun is stored as chemical energy in products formed during photosynthesis.

Overall reaction of photosynthesis

In chemical terms, photosynthesis is a light-energized oxidation-reduction process. (Oxidation refers to the removal of electrons from a molecule; reduction refers to the gain of electrons by a molecule.) In plant photosynthesis, the energy of light is used to drive the oxidation of water (H ₂O), producing oxygen gas (O ₂), hydrogen ions (H⁺), and electrons. Most of the removed electrons and hydrogen ions ultimately are transferred to carbon dioxide (CO ₂), which is reduced to organic products. Other electrons and hydrogen ions are used to reduce nitrate and sulfate to amino and sulfhydryl groups in amino acids, which are the building blocks of proteins. In most green cells, carbohydrates-especially starch and the sugar sucrose-are the major direct organic products of photosynthesis. The overall reaction in which carbohydrates-represented by the general formula (CH ₂O)-are formed during plant photosynthesis can be indicated by the following equation:

This equation is merely a summary statement, for the process of photosynthesis actually involves numerous reactions catalyzed by enzymes (organic catalysts). These reactions occur in two stages: the "light" stage, consisting of photochemical (i.e., light-capturing) reactions; and the "dark" stage, comprising chemical reactions controlled by enzymes. During the first stage, the energy of light is absorbed and used to drive a series of electron transfers, resulting in the synthesis of ATP and the electron-donor-reduced nicotine adenine dinucleotide phosphate (NADPH). During the dark stage, the ATP and NADPH formed in the light-capturing reactions are used to reduce carbon dioxide to organic carbon compounds. This assimilation of inorganic carbon into organic compounds is called carbon fixation.

During the 20th century, comparisons between photosynthetic processes in green plants and in certain photosynthetic sulfur bacteria provided important information about the photosynthetic mechanism. Sulfur bacteria use hydrogen sulfide (H ₂S) as a source of hydrogen atoms and produce sulfur instead of oxygen during photosynthesis. The overall reaction is

In the 1930s Dutch biologist Cornelis van Niel recognized that the utilization of carbon dioxide to form organic compounds was similar in the two types of photosynthetic organisms. Suggesting that differences existed in the light-dependent stage and in the nature of the compounds used as a source of hydrogen atoms, he proposed that hydrogen was transferred from hydrogen sulfide (in bacteria) or water (in green plants) to an unknown acceptor (called A), which was reduced to H ₂A. During the dark reactions, which are similar in both bacteria and green plants, the reduced acceptor (H ₂A) reacted with carbon dioxide (CO ₂) to form carbohydrate (CH ₂O) and to oxidize the unknown acceptor to A. This putative reaction can be represented as:

Van Niel's proposal was important because the popular (but incorrect) theory had been that oxygen was removed from carbon dioxide (rather than hydrogen from water, releasing oxygen) and that carbon then combined with water to form carbohydrate (rather than the hydrogen from water combining with CO ₂ to form CH ₂ O).

By 1940 chemists were using heavy isotopes to follow the reactions of photosynthesis. Water marked with an isotope of oxygen ( ¹⁸O) was used in early experiments. Plants that photosynthesized in the presence of water containing H ₂ ¹⁸O produced oxygen gas containing ¹⁸O; those that photosynthesized in the presence of normal water produced normal oxygen gas. These results provided definitive support for van Niel's theory that the oxygen gas produced during photosynthesis is derived from water.

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Photosynthesis | Definition, Formula, Process, Diagram, Reactants, Products, & Facts

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photosynthesis, the process by which green plants and certain other organisms transform light energy into chemical energy. During photosynthesis in green plants, light energy is captured and used to convert water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds. It would be impossible to overestimate the importance of photosynthesis in the maintenance of life on Earth.

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Picture of Photosynthesis

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Photosynthesis explanation video

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CHAPTER 5 PROCESS OF PHOTOSYNTHESIS (#1)

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CHAPTER 5 PROCESS OF PHOTOSYNTHESIS (#1)

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The process of photosynthesis is used by most autotrophs. This process allows them to make their own food. The process begins with the Sun. The autotrophs use energy from it to convert H20 (water) from the surrounding soil. They also use CO2 (carbon dioxide) from the air. These two components mix to form glucose. Glucose is a sugar that becomes food for the autotrophs. The glucose is then transformed into pyruvate. Pyruvate is a result of glycolysis. From here, it releases adenosine triphosphate (ATP) through a process called cellular respiration. Oxygen is then released into the air at the end of this process.